Purifying rubber or gutta-percha.



UNITED sTA-Tns PnTENT onirica.

WILHELMsLsNna AND ofrfro Marsans-HANOVER, eiiimnaiix.

rUnIrYING RUBBER on eumrariincim.

No Drawing.

lb all whom it may concern:

Be it known that we, WILHELM vvELSNE and OTTO Mavim, citizens of the German- Empire, residing at Hanover, Germany, have invented certain new and useful Improveinents in' Purifying Rubber or Gutta- Perclia, of which the folloiving is a specification.

This invention relates to improvements in the manufacture of pure rubber from crude rubber,.crude gutta percha, and the like. v

The materials brought on t0 ,the market under the general name of crude rubber or crude gutta percha. such as dead Borneo,

generally contain an appreciable quantityl of resinous substances which prevent the materials in question from being used withoutpurification.A For manufacturing amorcer( less vpure rubber from. the crude material 'the' saidresinous substances must be'removed,`^

' tone,and consisting chiefly of a mixture of Various aliphatic ketones.` The boiling point of these acetone oils is higher than that of' the acetone, and consequently ,itis possible to' carry out the extraction at a higher temperature Wit-hout loss by evaponation of thesolvent and thus a quicker and more complete` extraction is possible.

As acetone oils, unlike acetone, are practically insoluble in Water the extraction of crude rubber or crude gutta percha with these oils offers the following advantages 1. The Water always contained in the raw material-crude rubber orcrude gutta per-y cha-does not pass during the extraction l into the acetone oils and therefore cannot lAnother advantage: in the use Speccationof Letters Patent.. Ptented 1911. Application tiled.4 November 1.0,-1910. Serial No. 591,682. A

dilute themandimpair their resin-dissolving propertiesbut, being of greater specific gravity, .settles underthe acetone oils' and can be separated vfrom the solutionof resin.

2. Water canbe added to the acetone oils during the extraction in order to withdraw from the crude material substances such as v vegetable acids, salts, albumen,l etc., which are insoluble in acetone oil. 3. The water vegetable acids, albumen, etc.

Afterthe resinous substances have been l removed from the crude material the watery solution and the acetone oils containing the resins can be vseparated from each .other easily andthe acetone oils can be recovered almost completely.

The addition of other substances, such as alcohols and esters, exercises a favorable inuence on the l'process of extraction of crude' rubber Withacetone oils.

oils is that they do not exercisel any injuriousinfl-uence on the human skin.

After the treatment of rubber or gutta perchacontaining substances with acetoney oil by a cold or hot rocess and with or Without the addition o alkaline solutions, alcohols or esters, the -rubber or gutta percha remains undis'solved While the resinous substances can be obtained from the acetone oil solution containing them by distilling olf the solvent.

Having now particularly *described and ascertained the nature of`our said invention and in what manner the same is to be performed,'we declare that what We claim is of Vacetone 1.' A process for obtaining pure rubber or Y '.gutta percha, Which consists in extracting the resins and water soluble impurities therefrom' by treating the same lwith acetone oils. l ,2. The process of purifying rubber or 4gatta" 'percha which consists in extracting the resins and Water-soluble impurities therefrom by treating the same with acetone oils and adding to the said oils water.

3. The process of purifying rubber or gu'tta percha which consists in extracting the resins and Winter-soluble impurities In testimony whereof we aflxl our signatherefrom by treating the same with acetone tures in presence of two witnesses.

oils and adding to the sajid oils water, then WILHELM IELSNER, separating.' the watery solution of the eX- OTTO 5 tractingiquid from the acetone oils con-y Witnesses:

taining the resins and then recovering the J. M. BowoocK, acetone oils .from the resin R. P. THOMPSON.

Washington, D. C.

Copies of this patent may be obtained-for ve cents each, by addressing the Commissioner of Patents. 

